Abstract: The invention relates to an axial piston machine of a kind that has a plurality of pistons each reciprocating in a respective cylinder in a direction substantially parallel or at an angle less than 30 degrees to a crankshaft axis. The crankshaft axis presents a crank that is at an angle to the crankshaft axis and to which a reciprocator is mounted. The reciprocator effects the controlled movement of the pistons in their cylinders via a connection mechanism that connects each said piston with said reciprocator. The machine includes at least one pair of rotational constraint mechanisms to constrain the movement between the reciprocator and the pistons.

Abstract: A reciprocator restraint assembly for a Z-crank axial piston machine is described. The assembly includes two gimbal arms each linked together at gimbal link joint that intersect at a point T. Point T lying in a medial plane M being defined as the plane passing through the point of coincidence of the crank and crankshaft axes to which the line that bisects the crank angle is normal. Each of the gimbal arms is pivotally mounted at an identical distance L from point T. A cylinder gimbal is pivotally mounted from the cylinder cluster and a reciprocator gimbal is pivotally mounted from the reciprocator. The reciprocator gimbal pivot axis is equidistant from point X and T as is the cylinder gimbal pivot axis.